


Who Needs Privacy, Anyway?

by iqom



Category: Undertale (Video Game)
Genre: Anal Sex, Awkward Sexual Situations, Blow Jobs, Humor, M/M, Mortifyingly cringy situation, Overhearing Sex, Poor Sans, Sexual Humor, Shameless Smut, Smut, mention of handcuffs, not fontcest, papyton
Language: English
Status: Completed
Published: 2018-01-27
Updated: 2018-01-27
Packaged: 2019-03-10 03:05:08
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,904
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13494500
Author URL: https://archiveofourown.org/users/iqom/pseuds/iqom
Summary: Sans is being kicked out of his own house because Papyrus' robot boyfriend is going to be spending the night. Now, all he has to do is pack his things and leave before evening... unfortunate if he were to fall asleep and Papyrus doesn't realize he's still there.





	Who Needs Privacy, Anyway?

**Author's Note:**

  * For [Camilla Richard](https://archiveofourown.org/gifts?recipient=Camilla+Richard).



> Humor me, for a moment, as I take a trip down memory lane, back to 2009 on Fanfiction.net where babybones me (newly writing terribad fanfic for the Septimus Heap trilogy) had their first experience with naughty fanfiction; a piece called "Who Needs Privacy Anyway?". I read it about six billion times.  
> [The fic still exists, amazingly. ](https://www.fanfiction.net/s/5248225/1/Who-Needs-Privacy-Anyway)  
> As this particular fic heavily inspired me to begin writing smut myself down the road, I decided I needed to whip up a little something in honor of that: Undertale style.  
> Here's to you, Camilla, a good nine years later. *raises glass of sherry* Cheers.

“Sans?”

Sans knew that tone. The soft pitch, the hesitant upward inflection, the clear faltering in his brother’s voice; it was all very suspicious.

Papyrus usually yelled his name. When he didn’t, that meant _something was up._

“Yeah?”

“Could I possibly… ask you for a favor?”

Sans focused hard on the soggy marshmallows floating in his cereal, waiting for Papyrus to continue. Somehow, he had a feeling about where this was going.

“So Mettaton--” _Yup. Knew it._ “--was thinking of coming over tonight. Alphys and Undyne are having a date night, apparently, and they’ve kicked Mettaton out of his apartment. So! We figured we’d have our own! Doesn’t that sound nice?”

“Yeah. Sounds like a _Metta-ton of fun_.”

Papyrus glowered. “You’ve used that one at least five trillion times, Sans! It’s not funny anymore!”

Sans cracked a smile. “It’s a little funny.”

“ _Anyway…”_ Papyrus clacked his finger bones together nervously. Both brothers were avoiding each other’s gaze now. “Where _you_ come into this is… well, Mettaton needs a place to stay the night, obviously, and being the great and thoughtful boyfriend that I am, I thought, ‘what better place than here?’ Haha...”

“Are you asking my permission? ‘Cuz it’s your place too, bro. Mettaton can stay over whenever he wants.”

“R-right, yeah… I-I appreciate that, brother, thank you. But, see, what I was _wondering…_ was, ahem... do you… happen to have… a _location…_ to sleep, _hypothetically speaking…_ that’s not…well, here?”

Sans blinked slowly, a cold shiver of surprise and mortification scampering up his back as the implications of his brother’s request fully came to light. _Jesus fucking Christ._

“Um! Wait… _really?_ I mean… no, okay, but you guys…” Sans finished his jumbled attempt at a sentence with a high-pitched whine of devastation.

 _Of course_ Papyrus knew about sex. Sans was aware of this. His brother was a full-grown skeleton at the ripe old age of twenty-two, and he spent almost every weekend at Alphys and Mettaton’s place; Sans assumed the couple weren’t just sitting around and playing checkers.

He had, however, never _expressly considered_ this. Sans didn’t bring up his (nearly non-existent) sex life, Papyrus followed suit, and all was right with the world.

Sans wasn’t stupid. He knew what this “favor” was all about. Papyrus, his little bro (who seemed to have been just a babybones two minutes ago, what the hell happened?), was _sexiling him_ from his own house.

Papyrus looked alarmed. “Y-You can say no! Really, it’s fine! Mettaton and I c-can, I don’t know… find a h-hotel--”

“ _N-NO, YOU KNOW,_ that’s totally fine, you don’t have to do that,” Sans interrupted hurriedly, not wanting any more details, “I’ll spend the night at that motel on 8th, they have a sports bar, it’s all good.”

Papyrus looked relieved; partially because Sans had agreed, _mostly_ because he wasn’t being forced to elaborate further. “ _Thank you,_ brother, I really appreciate it! I owe you!”

“Yeah, you do…” Sans muttered to himself as Papyrus floated happily from the kitchen. He considered his cereal for a few moments before getting up to dump it in the trash.

* * *

 

Sans found himself haunted by the prospects of his brother’s impending evening all throughout the day.

The brothers lived in a ranch-style house together. A _house._ Sure, Sans’ bedroom was directly across the way from Papyrus’, but it’s not like the walls were absolute paper. How loud were they planning on being…?

The thought was like a fat, gross, annoying bug, buzzing through Sans’ ear canal and making itself all too comfortable in his mind. The last time this happened was back in the Underground, when Mettaton’s television show first hit the screens and Sans was naive enough to think wandering into his brother’s room without knocking first was a good idea. He had heard Mettaton’s voice faintly from the other side of the door, busted in to tease then-teenage Papyrus about it (“Watching that quiz show crap again? Looks like you’ve really hit rock _robottom_ ” _)..._ saw what he saw, turned an immediate one-eighty on his heel and went to take a long, cold shower.

A part of Sans urged him to just _grow up, already._ Papyrus certainly had; he was having his new boyfriend over for a romantic--and apparently _steamy--_ date night. Somehow, Sans found it difficult picturing Papyrus serving Mettaton a glass of wine, tossing around flirtatious remarks, hell, even _laughing at appropriate times;_ his brother had always been a pinnacle of awkwardness, as much as the very cool dude himself liked to believe otherwise.

Sans shoved some clothes from his floor unceremoniously into an overnight bag. The other part of him was thoroughly put off. And tired. _Really_ tired. That wasn’t new. _God, maybe I should have made them get a hotel after all?_

Sans tossed his half-packed bag to the corner of the room and flopped face down on the bed, exhausted by Papyrus, exhausted by that D-list celebrity… _D… oh, Christ, stop thinking about it…_

Simply, utterly exhausted. Sans allowed his eyes to close for a moment.

* * *

 

Sans woke up with a start to the sound of raucous laughter. _Wha…?_

It was nighttime, as indicated by the fact that his room was only illuminated by the lava lamp on his desk. He rubbed his eyes, trying to gather his disjointed thoughts.

 _Thud._ A loud banging noise against the door sent Sans rocketing into an upright position. _What the hell?_

He opened his mouth to call Papyrus’ name--

“I suppose we _do_ have your brother to thank for bringing us together… hiring him for stand-up at the resort was the best decision I ever made!”

Mettaton. That was Mettaton’s voice. _Wait. What?_

_Oh._

_Shit._

There was no way in _fuck_ Papyrus could know he was still in the house. He would just sit here in dead silence, his index phalanges firmly lodged in his ear canals and thinking of fields of wheat or _something_ until they had taken care of business across the way, and they could all go on living their merry lives without any embarrassment on anyone’s end. Relatively speaking...

_Why is the doorknob jiggling?_

“That’s why we should start here, my shining star! Nyeheh--mmm...”

Quick as a flash, Sans rolled out of his bed with the dexterity of an Olympic gymnast and shimmied underneath it. _You’ve gotta be fucking kidding m--_

Papyrus wasn’t kidding. Sans’ door swung open, light flooded the room, and he watched in absolute horror as two pairs of feet stumbled clumsily closer. The sounds they made as they (Sans assumed) sloppily kissed while walking were bonechilling; so bonechilling, in fact, that Sans couldn’t even take note of the potential pun.

There was a soft _thump_ as the couple collapsed on the mattress above him. Sans kicked himself internally for not making a break for the window, or _at least_ the closet.

“Doing it in your brother’s bed, hmm? Tsk. How _naughty,_ ” Mettaton purred.

“You know me!” Papyrus trilled cheerfully. Mettaton giggled. Sans slapped a hand over his mouth to keep from audibly gagging as _the sounds_ started up again. _Why does he kiss like he’s eating spaghetti? Christ, Paps…_

There was much shuffling and rustling from above. Sans considered time-traveling _the fuck_ out of there, but the tell-tale crack of electrical magic would alert the couple of his presence. Even worse than the current nightmare of a predicament would be his brother thinking he had been hiding under there _on purpose,_ trying to listen in.

When a pair of checked boxers landed on the floor in front of him, Sans began to seriously wonder whether it was really worse to just _run_ and then never speak to Papyrus ever again.

“Ah! A brilliant way to begin, my sweet!”

“Mhm… open your legs a touch more, darling… are you ready?”

 _Hell no,_ thought Sans. “Your face always looks so spectacular, Mettaton, but I must say, it looks absolutely _stupendous_ next to my cock like that! Why don’t you give it a couple of licks, for starters?”

Sans desperately wished for the sweet embrace of death as slurping ensued. Papyrus moaned sharply, a sound Sans knew would haunt him to the grave, and the mattress shifted above him as his brother began to undoubtedly wriggle.

“Oh, _wowie…_ you sexy, _sexy_ rectangle, you.. Oh, God, just like that…”

A running repeat of _shut the fuck up, Papyrus, shut the fuck up, Papyrus,_ was playing in Sans’ head; perhaps a measure taken by his psyche to drown out what he was being forced to listen to. It wasn’t working too well, as Papyrus’ voice only grew louder and more whiny as time plodded on.

Suddenly-- “W-why’d you stop?”  _Thank fuck._

“You look like you’re getting a little close, dear… there’s just so much more  _fun_ to be had before that happens, don’t you agree?”

“O-oh! An astute observation! What do you suggest, my love?”

The bedsprings squeaked. “Hmm. Take a guess, darling.”

_Oh… no._

“Nyehe _heh!_ I love the way you think, M-- _a-aah!_ ”

The sound was cacophonous. Sans’ poor boxspring surely hadn’t gone through so much in its entire existence and it was now crying out in protest, the springs squealing and popping, the headboard clattering against the wall. Not to mention the deeply unsettling gasps and moans of pleasure from both parties above him.

Sans began to formulate a to-do list in an effort to distract himself.

_1) Wash the sheets_

That was a _must._ In fact, scratch that--

_1) Burn the mattress_

__2)__ _Find my own apartment as soon as possible--_

_"OH,_ _FUCK, METTATON! AH--GOD! YOU FUCKING--AH!--YOU FUCKING LIKE THAT?”_

Sans grimaced, his head spinning. Papyrus always scolded Sans for swearing. Hearing him cuss now was like a weird fever dream. _Oh God, don’t think about it, back to the list…_

_1) Burn the mattress_

“Mng, yes, darling, right there, oh my _god,_ you’re so hot, _yes baby_ , _hmnng--_ ”

_1) Oh for fuck’s sake, how long is this gonna fucking LAST--_

“ _AHH, CHRIST! I’M GONNA--I’M GONNA UNLOAD, YOU READY, PRINCESS?”_

Sans resignedly reflected back on his life-- the choices he’d made, the paths he’d taken-- and wondered what exactly it was that he did to deserve this.

After one more unholy shriek from Mettaton and a groan from Papyrus, _finally_ the two were finished--

“My turn now,” Mettaton hummed, “I’m desperate for you, darling.”

“I vote… that we take it… to my room…” Papyrus panted. He stood from the bed, his feet hitting the floor mere inches from Sans’ face.

“Oh, what? You’ve got a surprise for me in there?”

Papyrus turned and (judging by the rustling of sheets, Papyrus’ “up we go!”, followed by more of Mettaton’s incessant giggling) scooped the robot up in his arms. “That’s where I keep the cuffs, my sweet!”

Sans closed his eyes and smiled in defeat. He had assumed it to be absolutely impossible for him to be more disturbed than he already was by anything else that came out of his brother’s mouth that night. Oh, what a fool he had been.

The second the door clicked shut behind the couple, Sans sauntered over to the window and rolled out into the daffodils growing beneath it.

He lay still for a moment, sucking in the freezing air and staring up at the night sky, before slowly getting to his feet and making his way down the road towards that sports bar on 8th.

**Author's Note:**

> God, I don't think I've ever cringed so hard writing anything. XD  
> Shame me on anon: https://iqomton.tumblr.com/


End file.
